Starter construction



Ma 28, 1935. R E WIKE 2,002,561

STARTER CONSTRUCTION Filed Nov. 7, 1932 E? II 7 1 g HUM A l m." 1' J ll HI v gwwowfm Patented May 28, 1935 f umrso STATES PA'TsNTfoFFicE Claims.

- ,This invention relates to a device foruse in starting internal combustion engines and the like.

The-invention is directed more particularly to .5 a starting device of the above mentioned character which includes a gear or pinion which moves into and out of meshing engagement with another gear by traveling along a screw threaded or similar shaft.

1 The invention has as an object to improve the structure of the traveling gear or pinion to the end that this pinion will mesh readily with the gear tobe driven, will quickly move out of meshing engagement withthis gear after the engine 15' has been started and will not rebound into con-,

tact with thegear to be driven.

Numerous other objects and advantages of this invention will become more apparent as the following. description proceeds, particularly when reference is had to the accompanying drawing,

wherein:

Fig.- 1 is an elevational view showing a starting device constructed in accordance with the teachings of this invention;

Fig: 2 is a sectional view taken substantially on the line 2-2 of Fig. l; and

Fig. 3 is a perspective sectional view of a portion of the structure shown in Fig. 1.

7 Referring then particularly to the drawing wherein like reference characters designate corresponding parts throughout all views, the numeral Ill designates the flywheel of an internal combustion engine (not shown). This flywheel is provided on its periphery with teeth II adapted to be engaged by a driving pinion to impart rotation to the flywheel and to thus. start the engine. I

The numeral I2 designates the starting motor which may, in accordance with the usual practice, be an electric motor. Mounted on. the driven shaft I3 of this motor is a hollow shaft I4 provided with the screw threads I5. The shaft I4 is driven from the shaft I3 preferably by a yieldable connection such as the spring I6 suitably secured to the shafts I3 and I4 in any desired manner. The numeral 20 designates a pinion having internal screw threads 2I which engage the threads I5 on the shaft I4, so that upon relative rotation between shaft I 4 and pinion 20,.the latter moves longitudinally on the shaft I4. Pinion 20 isadapted to move from its de-meshed position shown in Fig.- lof the drawing, in which position 5 the end of the pinionabuts the; driving head of the shaft I 4 to aposition where its teeth mesh with'the teeth II on flywheel I0. I

The structure above describedis of standard construction and forms no part of the present invention. It is illustrated to disclose one type 5.

of starting device in which the present invention about to be described may be'incorporated.

It will be understood that in the operation, of the above described construction, the parts are normally in the position shown in Fig. 1 of the 10 drawing. ,When the starter switch (not; shown) is closed, the motor I2 is caused to rotate shaft. I3 and thus shaft I4. Due to the inertia of the pinion 20, the latter is threaded to the right on shaft I4, and theteeth of the pinion are thus 15- engaged with the teeth on the flywheel. The flywheel is thus driven :untilthe engine starts, at which time the flywheel rapidly rotates the pinion with reference to the shaft III. This causes the pinion to thread to the left on the shaft, thus returning the pinion to its de-meshed position, shown in Fig. l of the drawing.

In a construction of this character the pinion gear should have an eccentric counterweight at the time of closing the starter switch. Such an eccentric counterweight tends'to prevent rotation or spinning of the pinion, so that the same will thread to the right on the shaft I4 and thus move into meshing engagementwith the teeth on the flywheel.

Duringuthe cranking operation, however, the eccentric counterweight on the pinion gear should gradually change to a concentric counterweight bythe time the motoris ready to start, for the reason that if the counterweight is concentric, the starter pinion will act as a flywheel and thus spin rapidly'ah'ead of the shaft under the impetus given it by the flywheel III. This rapid spin-' ningof the pinion causes the same to de-mesh quickly. y

It might be stated that if the counterweight is eccentric at the time the engine starts, there is a tendency for the starter pinion to tilt or become cooked on the shaft I4, thus causing the pinion to bind on this shaft with the result that the de-meshing of thepinion is retarded. This re,- tardation causes a'dragging of the teeth of the pinion on the-teeth of the flywheel, resulting not only in a noisy operatiombut resulting also frequently in damage to the teeth of the flywheel and pinion gear;

As soonas the pinion gear reaches its full demeshed position and strikes the stop 22, it is necessary that the energy stored in the rotating pinion gear be dissipatedto prevent rebounding of the pinion gear back into engagement with the flywheel. Further, during this dissipation of the energy of the pinion gear, the concentric counterweight of the gear should gradually change to an eccentric counterweight, and the friction causing the dissipation of energy should be proportional to the speed of rotation of the pinion gear. It will be apparent that the changing of the concentric counterweight to an eccentric counterweight prepares the pinion gear for the next starting operation.

The present invention provides a pinion gear having the above discussed characteristics, by associating with this gear a movable weight. This weight is so constructed that it is normally eccentric to the axis of the pinion gear. When, however, the pinion gear is rotated, the movable weight becomes concentric with the axis-cf the gear. After the starting operation has been completed, the weight functions to dissipate the energy stored'in' the rotating pinion gear and gradually becomes again eccentric to the axis of the gear, so that the gear is prepared for the next starting operation; I a

The structure providing a weight capable of acting in this manner is shown more clearly in Figs. 2 and 3. By reference to these figures it will be noted that there is mounted on one end of the pinion gear a housing 25, and this housing provides an annular chamber 25 which extends circumferentially around the axis of the pinion. It will be understood that this housing may 'be formed in any desired manner and may be secured to the pinion in any convenient way. For the sake of illustration, the housing is shown as having the inner and outer walls 21 and 28, respectively, and the side walls and 30, the latter being secured to the inner and outer walls by bolts or the like 31. v

The annular chamber 26 is partially filled a mobile substance 35-, and: this substance constitutes the weight. Any number of different substances may be utilized, such, for example, as mercury, sand, small shot, iron filings, or in fact,

' any substance which will flow suflicien-tly freely to collect in the bottom of the annular chamber when the pinion is' stationary, in the manner illustrated in Fig. Zof the drawing.

Hingedly mounted in the annular chamber 26 and in spaced relation to each other are a plurality of doors 36; these doors being shown as being hinged as at 31' to the inner wali IT or the chamber. The doors are in the nature of check valves which open to allow the substance 35 to move in the direction of the arrow in Fig. 2' of the drawing, but which close against the'outer' wall 23 of the chamber to prevent the reverse or back flow of the substance. It i's'contemplated that there will be sufficient clearance between the hinges 37 and the inner wall 21 of the chamber to permit any of the substance which is trapped in the upper part of the chamber to how downwardly tothe bottom of the chamber when the pinionis stationary. 'If sufficient clearance is not obtainable at these points'the doors may be provided with reduced openings 38 through which the substance may flow, as will be readily apparent. If desired, the outer wall 28 of the chamber may be provided at spaced points with inwardly facing shoulders 39, these shoulders being so formed as to be impinged upon by the substance 35 when the latter moves within the chamber 23.

In operation and with the parts the posi tion shown in Fig. lot the drawing, it wilibe understood that the substance 35 will be in the bottom half or" the chamber 26. Thus this substance will provide an eccentric counterweight for the pinion gear 26. If now, the starter motor I2 is actuated to rotate shaft M, the pinion 20 will, by virtue of its threaded engagement with the shaft and by virtue of its inertia, move to the right into engagement with the teeth II on the flywheel It. The eccentricity of the counterweight will tend to prevent the pinion from rotating, so that the pinion will readily thread to the right on the shaft and properly mesh with "the teeth I I.

After the pinion has become engaged with the teethl-i, continue-d rotation of the pinion will cause: a rotation of flywheel l0 and thus a cranking of the engine. During this cranking operation, the substance 35 will gradually be moved by centrifugal force until it becomes distributed uniformly in the chamber 26, the doors 36 opening readily to permit this even distribution of the weight substance 35. Thus, during the cranking operation, the counterweight will gradually change from its eccentric position to a concentric position. It might be stated that when the pinion meshes with the teeth on the flywheel, the shock of this meshing engagement aids in distributing the substance 35 uniformly within the chamber 26.

*As soon as the engine starts, the flywheel in will cause the pinion to rotate faster than the. shaft M. By virtue of the fact that the counterweight is at this time concentric with the ans of the pinion, the pinion will act as a flywheel and thus move quickly to the left or to its demeshed position. Even though a quick rotary impulse is given to the-pinion gear at the time that the engine starts, the concentricity of the counterweight is not destroyed for the reason that the doors 35 close and thus prevent the housing from moving ahead of the substance 35. The substance becomes trapped between the several doors and remains evenly distributed within. the chamber 26 so that its even distribution about the axis of. the pinion gear is not destroyed. As

brought out before, it might be stated that during this ole-meshing operation it is important that the counterweight be not eccentric to the pinion 'for the reason that when the counterweight is eccentric, it tends to cause a binding of the pinion on the threaded shaft on which it is mounted, thus retarding to a substantial extent the d'e-meshing operation.

As soon as the pinion gear hits the stop 22,. the moment of inertia of the substance 35 causes this substance to continue its travel within the chamber 26 and about the axis of the piniongear. This dissipates the energy stored in the rotating pinion gear and prevents the same from rebounding from the stop 22 and into engagement with the flywheel it. Obviously, at this time the substance gradually returns to its position in the lower half of the chamber 25 and thus becomes again eccentric to the axis of the pinion gear.

It will be apparent that the friction between.

the substance 35 and the walls of chamber 26 and more particularly the outer wall thereof during the period when the energy in the rotating. pinion is dissipated, will be proportional to the speed of rotation of the pinion at the time the latter hits the stop 22. Thus the substance 35 will function to effectively dissipate this energy, regardless of the speed of rotation of the pinion gear at the instant that this gear hits the stop.

The shoulders 37 on the inner surface of theouter 75 wall of the chamber, facing as they do against the direction of movement of the substance 35, act to increase the frictional resistance to movement of the substance 35 within the chamber 26.

' It is to be understood that whatever material is selected as the substance 35, this material will be sealed within the chamber 26. This may be conveniently efiected by soldering or otherwise effectively securing the cover 38 to the inner and outer walls of the chamber. With the material sealed in the chamber in this manner, it will be apparent that there will be no loss of the material by leakage and no reaction of the material to atmospheric changes or the like.

It might be stated that if shot, iron filings or the like are utilized as the substance 35, a suitable quantity of lubricating oil might be added to increase the shiftability of this material. If, on the other hand, sand is utilized, the doors 36 may, if desired, be eliminated for the reason that the small particles of sand will adhere sufliciently to each other and to the inner surface of the outer wall of the chamber 26 to make the use of the doors 36 unnecessary.

It has been stated before that the shoulders 39 are so arranged that they will resist movement of the substance 35 within the chamber 26. It might be stated, however, that these shoulders serve an additional function, namely that of aiding in maintaining the drive pinion adjacent the stop 22.

By reference to Fig. 2, of the drawing, it will be noted that the shoulders are so arranged that those on the right hand side of the axis of the pinion gear, as viewed in Fig. 2, face upwardly. When the pinion gear is in its de-meshed position, the constant motor vibration tends to cause the substance 35, particularly if this substance be sand, to pile up on the shoulder or shoulders at the right hand side of the axis of the pinion gear, thus slightly adding to the weight on this side of the axis. This slight additional weight prevents the pinion gear from moving or creeping away from the stop when subjected to continuous vibration, tending rather to cause the pinion gear to creep in a direction which will move it toward the stop 22.

From the above it will be apparent that the invention provides a counterweight adapted to be associated with the pinion gear of a starter construction and capable of changing from a position eccentric tothe axis of the pinion gear to a position concentric with reference to said axis. Further, the movement or shifting of the counterweight will be entirely automatic, with the result that the pinion gear will at all times be properly counterweighted to effect the desired results.

While the invention has been described as be: ing incorporated in the pinion gear of an engine starter construction, it is to be understood that the inventive principles disclosed may be incorporated in other constructions wherein it is desired to have a counterweight capable of shifting in the manner described. Still further, while the mobile substance which constitutes the counterweight has been shown as being housed in a chamber located at one end of the pinion gear, it will be apparent that, if desired, this chamber might extend the length of the pinion gear, the teeth on the pinion gear being formed in this case on the outer surface of the outer wall 28 of the chamber. These and numerous other changes may be made in the details of construction and arrangement of parts, so that it is to be understood that this description is for the purposes of illustration only and is not definitiveof the limits of the inventive idea, the right being reserved to make such changes as will fall within the purview of the attached claims.

. What I claim as my invention is:

1. In a starter construction, the combination with a threaded shaft, a threaded pinion thereon, and a gear to be started by the pinion, of means carried by said pinion providing a sealed annular chamber surrounding the axis of rotation of the pinion, and a quantity of a mobile substance in said chamber and constituting a weight for said pinion.

2. In a starter construction, the combination with a starter pinion, of means carried by said pinion and providing an annular chamber surrounding the axis of rotation of the pinion, a quantity of a mobile substance in said chamber and partly filling the same, and baffles hing edly mounted at spaced points in said chamber for restraining the said mobile substance against movement in one direction in said chamber.

3. In a drive for an engine starter, the combination of a rotatable screw member, a member screw-threaded thereon and capable of longitudinal movement thereof and rotary movement therewith, means providing an annular cham ber surrounding said member, a quantity of a mobile substance in said chamber and partly filling the same, baiiles hingedly mounted at spaced points in said chamber, and means providing shoulders projecting interiorly of said chamber from the outer wall thereof.

4. In a starter construction, the combination with a rotatable threaded shaft, a pinion thread ed on said shaft for axial movement relative thereto, and a gear adapted to mesh with said pinion upon a predetermined axial movement of the latter providing for rotation of the pinion by the shaft, of a mobile substance constituting a weight for said pinion and normally disposed at one side of the axis of the pinion to assist movement of the latter axially of said shaft.

5. In a starter construction, the combination with a rotatable threaded shaft, a pinion threaded on said shaft for axial movement relative thereto, and a gear adapted to mesh with said pinion upon a predetermined axial movement of the latter providing for rotation of the pinion by the shaft, of a mobile substance constituting an eccentric weight for said pinion when the latter is out of mesh with said gear and responsive to the rotation of the pinion to become evenly distributed around the axis of the latter.

REGINALD E. WIKE. 

